856442880 has 144 divisors (see below), whose sum is σ = 2968596540. Its totient is φ = 228360192.

The previous prime is 856442869. The next prime is 856442903. The reversal of 856442880 is 88244658.

856442880 is a `hidden beast` number, since 8 + 564 + 4 + 2 + 8 + 80 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 769729536 + 86713344 = 27744^2 + 9312^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 87514 + ... + 96806.

Almost surely, 2^856442880 is an apocalyptic number.

856442880 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 856442880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1484298270).

856442880 is an abundant number, since it is smaller than the sum of its proper divisors (2112153660).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

856442880 is a wasteful number, since it uses less digits than its factorization.

856442880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9326 (or 9303 counting only the distinct ones).

The product of its (nonzero) digits is 491520, while the sum is 45.

The square root of 856442880 is about 29265.0453613180. The cubic root of 856442880 is about 949.6556018475.

The spelling of 856442880 in words is "eight hundred fifty-six million, four hundred forty-two thousand, eight hundred eighty".